I won't go into much detail but in short, my PIP was extended by a month because my manager feels I am not there where he expects me to be.
And most recently, I have been assigned to work on one of most crucial systems in our infrastructure which would need my expertise because I have been the only one who has worked exclusively on that system in the past since its in the language that I have experience with.
Project is basically a rewrite of the system in another language that other team members are comfortable in. I will be working on one of components of the system alone & will be helping a senior developer along the way as well (he's working on different component of the system).
As far as I remember, this rewrite was not going to happen for at least few months.
One of the main concerns for me has been job hunt side by side. I have had 3 interviews so far and no concrete progress yet, so I don't think I will be able to score a job offer before PIP ends.
I have sufficient savings to back myself up so I can resign without any fear of finances. In fact I have a resignation letter signed & ready right now in my bag.
So, what would be the downside(s) / repercussion(s) of leaving while I have been assigned to a major rewrite? Moreover, my manager feels that this project will probably be crucial in deciding where I stand.